<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>

<body>
<script>


var s = "abcdefghijklmn";
var r = /(a(b(c)))/;
var a = s.match(r); 		// 返回数组["abc", "abc" , "bc" , "c"]

					// 返回""

</script>
</body>
</html>
